Conventionally, a vehicle has a mechanical relay for blinking a direction indicator lamp and a hazard lamp. According to operation of the direction indicator lamp or the hazard lamp, the direction indicator lamp or the hazard lamp is blinked. Furthermore, in order to confirm a blinking state of the direction indicator lamp or the hazard lamp in the vehicle by a driver, its state is indicated with an indicator. For this reason, visual information is provided, and also auditory information is provided by hit sound of the mechanical relay.
In recent years, a flashing operation of the direction indicator lamp and the hazard lamp is performed by using a semiconductor switch. In such case, the mechanical relay is not provided, and as a result the hit sound for confirming auditory information is not obtained.
In order to solve the above problem, conventionally, the buzzer intermittently sounds as the hit sound of the mechanical relay. In the hit sound of the mechanical relay, generally as shown in FIG. 7, spectrum is spread in wide frequency band. However, as shown in FIG. 8, in a general sounding state of the buzzer, only fundamental wave and high-frequency wave are indicated in the spectrum, and the spectrum is not spread in wide frequency band as the hit-sound of the mechanical relay. For this reason, the buzzer differs considerably from the hit sound of the mechanical relay, and thereby causes a feeling of strangeness.
Furthermore, as shown in FIG. 9, a device for generating display sound of a direction indicator disclosed in the Patent Document 1 intermittently outputs an operation signal, which does not arrived at current-carrying time or current-carrying capacity required to sound a sounding body with steady-state operation-sound, to the sounding body (piezoelectric vibrator) of a horn in synchronization with a direction indicator blinking signal. As a result, a sound distinctly-different from the sound of the horn and similar to the familiar the hit-sound of the mechanical relay is generated.
However, in the device for generating the display sound of the direction indicator disclosed in the Patent Document 1, an electric current is applied in a short time failing to reach the current-carrying time required to sound the horn with the steady-state operation-sound. For this reason, in a place where various operation sound or environmental sound is generated, for example, in the vehicle, a driver can not recognize the sound of the horn as the hit-sound of the mechanical relay.